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Abstract:

In one aspect, a needle assembly is provided herein which includes a hub;
a needle fixed to the hub, the needle having a proximal end and a distal
end, the distal end formed for insertion into a patient; and, a body
disposed on the hub so as to be moveable relative thereto, the body
having a distal end with an aperture formed therein configured to permit
passage therethrough of the needle. The body is releasably retainable in
a first position on the hub where the distal end of the needle extends
distally a first distance from the distal end of the body. Also, the body
is retainable in a second position on the hub where the distal end of the
needle extends distally a second distance from the distal end of the
body, the second distance being less than the first distance. The hub is
displaceable proximally relative to the body to urge the body from the
first position to the second position. Advantageously, with the subject
invention, a needle assembly is provided which may provide a stop for a
needle injection to a first depth, with the stop being adjustable to
permit the injection to be conducted at a shallower, second depth.

Claims:

1. A needle assembly comprising: a hub; a needle fixed to said hub, said
needle having a proximal end and a distal end, said distal end formed for
insertion into a patient; and, a body disposed on said hub so as to be
movable relative thereto, said body having a distal end with an aperture
formed therein configured to permit passage therethrough of said needle;
wherein, said body being releasably retainable in a first position on
said hub where said distal end of said needle extends distally a first
distance from said distal end of said body, wherein, said body being
retainable in a second position on said hub where said distal end of said
needle extends distally a second distance from said distal end of said
body, said second distance being less than said first distance, and,
wherein, said hub is displaceable proximally relative to said body to
urge said body from said first position to said second position.

2. A needle assembly as in claim 1, wherein said body is fixedly
retainable in said second position on said hub.

3. A needle assembly as in claim 1, wherein said body is releasably
retainable in said second position on said hub.

4. A needle assembly as in claims 3, wherein, said body is fixedly
retainable in a third position on said hub where said distal end of said
needle is located proximally of said distal end of said body.

5. A needle assembly as in claim 4, wherein said hub is displaceable
proximally relative to said body to urge said body from said second
position to said third position.

6. A needle assembly comprising: a hub; a needle fixed to said hub, said
needle having a proximal end and a distal end, said distal end formed for
insertion into a patient; a body disposed on said hub so as to be movable
relative thereto, said body having a distal end with an aperture formed
therein configured to permit passage therethrough of said needle; and, a
pressure sensitive adhesive disposed on said distal end of said body,
wherein, said body being releasably retainable in a first position on
said hub where said distal end of said needle extends distally a first
distance from said distal end of said body, wherein, said body being
retainable in a second position on said hub where said distal end of said
needle extends distally from said distal end of said body less than said
first distance from said distal end of said body, or is located
proximally of said distal end of said body, and, wherein, said adhesive
is configured to provide sufficient adherence to a patient's skin during
an injection such that said body remains relatively fixed to the
patient's skin to permit proximal movement of said hub relative to said
body with said body being moved from said first position to said second
position.

7. A needle assembly comprising: a hub; a needle fixed to said hub, said
needle having a proximal end and a distal end, said distal end formed for
insertion into a patient; a body disposed on said hub so as to be axially
and radially movable relative thereto, said body having a distal end with
an aperture formed therein configured to permit passage therethrough of
said needle; a spring element for urging said body distally away from
said hub; and, a cooperatively coupled cam track having at least a first
position and a second position and cam follower wherein the cam track is
disposed either on the body or the hub and the cooperating cam follower
is disposed on the opposing part, thereby constraining relative axial
motion between said hub and body, wherein, said body being releasably
retainable in a first position where said distal end of said needle
extends distally a first distance from said distal end of said body,
wherein, said body being retainable in a second position on said hub
where said distal end of said needle extends distally from said distal
end of said body less than said first distance from said distal end of
said body, or is located proximally of said distal end of said body, and,
wherein, said cam track and said cam follower cooperate during an
injection procedure to permit distal axial movement of said body, biased
by said spring, with said body being moved from said first position to
said second position after a predetermined extent of radial motion
between said body and said hub.

8. A needle assembly as in claim 7, wherein said body is fixedly
retainable in said second position on said hub.

9. A needle assembly as in claim 7, wherein said body is retained in said
second position on said hub by a detent in said cam track.

10. A needle assembly as in claim 7, wherein, said cam track has a third
position and said body is fixedly retainable in said third position where
said distal end of said needle is located proximally of said distal end
of said body.

Description:

FIELD OF THE INVENTION

[0001] This invention is directed to needle assemblies and, more
particularly, to needle assemblies for permitting depth adjustment for
injection.

BACKGROUND OF THE INVENTION

[0002] Medical injections of different depths, such as subcutaneous and
intradermal injections, are known in the art. It is also known in the
prior art to utilize a hard stop provided about a needle to ensure proper
depth during injection.

[0003] In addition, sealing may be of concern during certain injections,
particularly with shallow injections, such as intradermal injections. It
has been found that a blister or wheal may form in the skin in which
injected fluid collects as a pocket. Built-up pressure may cause the
injected fluid to seep out the injection passage during or after
injection.

SUMMARY OF THE INVENTION

[0004] In one aspect, a needle assembly is provided herein which includes
a hub; a needle fixed to the hub, the needle having a proximal end and a
distal end, the distal end formed for insertion into a patient; and, a
body disposed on the hub so as to be moveable relative thereto, the body
having a distal end with an aperture formed therein configured to permit
passage therethrough of the needle. The body is releasably retainable in
a first position on the hub where the distal end of the needle extends
distally a first distance from the distal end of the body. Also, the body
is retainable in a second position on the hub where the distal end of the
needle extends distally a second distance from the distal end of the
body, the second distance being less than the first distance. The hub is
displaceable proximally relative to the body to urge the body from the
first position to the second position. Advantageously, with the subject
invention, a needle assembly is provided which may provide a stop for a
needle injection to a first depth, with the stop being adjustable to
permit the injection to be conducted at a shallower, second depth.

[0005] In a further aspect, the subject invention provides a needle
assembly having a hub; a needle fixed to the hub, the needle having a
proximal end and a distal end, the distal end formed for insertion into a
patient; a body disposed on the hub so as to be moveable relative
thereto, the body having a distal end with an aperture formed therein
configured to permit passage therethrough of the needle; and, a pressure
sensitive adhesive disposed on the distal end of the body. The body is
releasably retainable in a first position on the hub where the distal end
of the needle extends distally a first distance from the distal end of
the body. Also, the body is retainable in a second position on the hub
where the distal end of the needle extends distally from the distal end
of the body less than the first distance from the distal end of the body,
or is located proximally of the distal end of the body. The adhesive is
configured to provide sufficient adherence to a patient's skin during an
injection such that the body remains relatively fixed to the patient's
skin to permit proximal movement of the hub relative to the body with the
body being moved from the first position to the second position.

[0006] As used herein, the term "distal", and derivatives thereof, shall
refer to a direction towards a patient during use, and the term
"proximal", and derivatives thereof, shall refer to a direction away from
a patient during use.

[0007] These and other features of the invention will be better understood
through a study of the following detailed description and accompanying
drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a front perspective view of a needle assembly formed in
accordance with the subject invention;

[0009] FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1;

[0010] FIG. 3 is an enlarged section of Section 3 of FIG. 2;

[0011] FIG. 4 is an enlarged section of Section 4 of FIG. 6;

[0012] FIG. 5 shows the same needle assembly of FIG. 1, but in a second
position;

[0013] FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 5;

[0014] FIGS. 7 and 8 show first and second positions of a needle assembly
formed in accordance with the subject invention;

[0015] FIG. 9 is a cross-sectional view of a variation of a needle
assembly formed in accordance with the subject invention;

[0016] FIG. 10 is an enlarged section of Section 10 of FIG. 9; and,

[0017] FIGS. 11 and 12 show different track arrangements useable with the
subject invention.

DETAILED DESCRIPTION OF THE INVENTION

[0018] With reference to the Figures, a needle assembly 10 is provided
which is formed to provide depth adjustment for medical injections. The
needle assembly 10 may be utilized with various injectors, but is
particularly well-suited for use with pen injectors.

[0019] The needle assembly 10 generally includes a hub 12, a needle 14
fixed to the hub 12, and a body 16 disposed on the hub 12 so as to be
moveable relative thereto. The body 16 acts as a stop and limits the
permissible depth of injection of the needle 14 into a patient, as
described below.

[0020] The hub 12 includes a tubular portion 18 and a transverse bulkhead
20 to which the needle 14 is attached in any known manner, such as with
adhesion. Preferably, the tubular portion 18 includes a reduced-diameter
neck portion 22 at its proximal end. The bulkhead 20 may span across the
interior of the tubular portion 18, particularly at the neck portion 22.

[0021] Mounting features 24 are provided on the tubular portion 18, either
interiorly and/or exteriorly thereof, formed to mount the needle assembly
10 onto a medical injector. The mounting features 24 may include a Luer
surface and/or threads, or other known mounting features. Preferably, the
hub 12 is formed of a material, e.g., thermoplastic material, which can
withstand autoclaving or other forms of sterilization.

[0022] The needle 14 may be of any known type and includes a proximal end
26 and a distal end 28 formed for insertion into a patient. The distal
end 28 may be sharpened. In addition, the proximal end 26 may be
sharpened and may be formed with sufficient length to extend through a
septum, or other closure, provided on a medical injector with the needle
assembly 10 being mounted thereto.

[0023] The body 16 includes a distal end 30 from which extends proximally
a skirt 32. Preferably, the skirt 32 is annular shaped and perimetrically
bounds the distal end 30. The skirt 32 is sized and shaped to telescope
over the neck portion 22 of the hub 12. An aperture 34 is formed in the
distal end 30 of the body 16 configured to permit passage therethrough of
the needle 14. The body 16 is preferably formed of a material, e.g.,
thermoplastic material, which can withstand autoclaving or other forms of
sterilization.

[0024] The body 16 is disposed on the hub 12 so as to be movable relative
thereto. Relative movement between the body 16 and the hub 12 can be
achieved by telescoping movement of the skirt 32 about the neck portion
22. The hub 12 and the skirt 32 may be formed so that sufficient
interengagement is generated therebetween to provide retentive force for
maintaining the skirt 32 on the hub 12.

[0025] With reference to FIGS. 1-8, it is preferred that the needle
assembly 10 be utilized such that the body 16, particularly the distal
end 30, acts as a hard stop in limiting the depth of an initial injection
of the needle 14 into a patient. Specifically, with reference to FIGS. 1,
2 and 7, a first position of the body 16 is shown, where, the distal end
28 of the needle 14 extends a first distance D1 from the distal end 30 of
the body 16 (FIG. 7). It is preferred that the body 16 be retained in the
first position relative to the hub 12 so as to act as a hard stop against
excessive insertion of the needle 14 into a patient. It is preferred that
the body 16 be releasably retained in the first position so as to permit
subsequent movement therefrom.

[0026] By way of non-limiting example, and with reference to FIGS. 2 and
3, a releasable retaining arrangement may be provided including one or
more retaining teeth 36 preferably formed on the body 16. A cooperating
first retention slot 38 is preferably formed on the hub 12. The retaining
teeth 36 are formed to be nestingly received in the first retention slot
38 in a limited snap engagement formation. The first retention slot 38 is
formed of limited depth such that the retaining teeth 36 may be released
from snap engagement with the first retention slot 38 and urged therefrom
under sufficient separating force. Preferably, the separating force is
generated by causing proximal movement of the hub 12 relative to the body
16.

[0027] A second retention slot 40, preferably formed on the hub 12, may be
formed proximally from the first retention slot 38. The second retention
slot 40 corresponds to a second position of the body 16 relative to the
hub 12 where, as shown in FIGS. 5, 6 and 8, the distal end 26 of the
needle 14 extends a distance D2 from the distal end 30 of the body 16.
The distance D2 is less than the distance D1. In this manner, the needle
14 may be initially inserted to a first depth in a patient with the body
16 being in the first position and, with the hub 12 being subsequently
moved proximally relative to the body 16, the body 16 may be urged to the
second position from the first position.

[0028] The body 16 may be fixedly retained in the second position on the
hub 12. To provide fixed retention, as shown in FIGS. 3 and 4, the second
retention slot 40 may be formed with greater depth than the first
retention slot 38 so as to cause the retaining teeth 36 to be fixedly
retained therein, thus inhibiting further relative movement of the hub 12
relative to the body 16. More particularly, the second retention slot 40
may be formed with sufficient depth to prevent release from snap
engagement with the retaining teeth 36. Alternatively, as discussed
below, the body 16 may be releasably retained in the second position on
the hub 12. Here, the second retention slot 40 may be formed in the same
manner as the first retention slot 38 (e.g., same depth) so as to be
configured to permit release by the retaining teeth 36 from snap
engagement therewith. As will be appreciated by those skilled in the art,
the retaining teeth 36, the first retention slot 38, the second retention
slot 40 and/or any further retention slot may be partially or wholly
formed on the hub 12 and/or the body 16 to operate in the same manner as
described herein.

[0029] The first and second positions may be configured to correspond to
particular injection depths for the needle 14. For example, the first
position may correspond to a subcutaneous injection, while the second
position may correspond to an intradermal injection. In addition, the
first position may correspond to an intramuscular injection, while the
second position may correspond to an intradermal injection, and likewise
depending on the selected distances, any combination of depths may be
employed thereby targeting two separate tissue compartments. In this
manner, the needle 14 may be injected to a first depth, then withdrawn to
a shallower depth for drug administration. By causing an initial deeper
injection (at the distance D1), better sealing may be achieved about the
needle 14 during the course of the drug administration at the shallower
injection (at the distance D2) corresponding to the second position of
the body 16 on the hub 12.

[0030] During use, it is preferred that the needle 14 be inserted into a
patient with the body 16 being in the first position (FIG. 7). The distal
end 30 of the body 16 acts as a hard stop to limit the depth of the
insertion of the needle 14 into a patient's skin S. Thereafter, and prior
to actuation of the injector to cause drug administration, the body 16 is
maintained against the patient's skin S and the hub 12 is caused to move
proximally relative to the body 16 so as to urge the body 16 into the
second position (FIG. 8). Proximal movement of the hub 12 may be achieved
by manual action, e.g., by holding the body 16 in one hand against the
patient's skin and causing proximal movement of the hub 12 relative to
the body 16, with the second hand (e.g., causing withdrawal of the hub 12
away from the patient's skin S). Actuation of the medical injector, and,
thus, drug administration, may be caused with the body 16 in the second
position.

[0031] Various modes of causing proximal movement of the hub 12 relative
to the body 16 may be utilized. As described above, relative proximal
movement may be caused manually. Alternatively, relative proximal
movement may be caused passively or caused by a combination of
manual/passive action (e.g., manual trigger with passive actuation).

[0032] By way of non-limiting example, to passively achieve relative
proximal movement of the hub 12 versus the body 16, a layer of pressure
sensitive adhesive 42 may be provided on the distal end 30 of the body 16
configured to provide sufficient adherence to a patient's skin during an
injection such that the body 16 remains relatively fixed to the patient's
skin to permit proximal movement of the hub 12 relative to the body 16
with the body 16 being moved from the first position to the second
position. Various pressure sensitive adhesives may be utilized with the
subject invention. The layer 42 may be arranged in various patterns,
including being continuous in bounding the needle 14 (e.g., such as being
disc-shaped) or discontinuous in random or regular patterns.

[0033] It is noted that the layer of pressure sensitive adhesive 42 should
not be excessively adherent in that the needle assembly 10 must be
ultimately removed from the patient. Discomfort to the patient caused by
removal of the layer 42 must be minimal. It is preferred that with the
body 16 being fixedly retained by the hub 12, e.g., fixedly retained in
the second position, a greater retentive force of the body 16 on the hub
12 is generated than the adherence of the layer 42 to the patient's skin
S. With this arrangement, the body 16 may be removed from the patient's
skin S with the body 16 maintaining a fixed position on the hub 12 and
with minimal discomfort to the patient.

[0034] As indicated above, proximal movement of the hub 12 relative to the
body 16 may be caused by a combination of manual and passive action. With
reference to FIGS. 9-12, and by way of non-limiting example, a variation
of the needle assembly 10 is shown which operates with a combination of
manual (i.e., active) and passive action. In particular, a manual trigger
is utilized to cause passive actuation. In this arrangement, a spring 44
is disposed between the hub 12 and the body 16 configured to urge the
body 16 distally away from the hub 12. The spring 44 may be of any known
type capable of generating a biasing force, including being of a coil or
compression type. To provide stability to the spring 44, a secondary wall
46 may be disposed inwardly of the neck portion 22 which defines a well
48 in which the spring 44 is seated. The well 48 may be disposed between
the bulkhead 20 and the neck portion 22, with the bulkhead 20 spanning
the interior of the body 16 between portions of the well 48. The spring
44 is positioned to preferably act against the distal end 30 of the body
16.

[0035] One or more cam followers or protrusions 50 are preferably formed
to extend inwardly from the body 16, particularly from the skirt 32.
Correspondingly, one or more cam tracks 52 are formed in the hub 12,
particularly at the neck portion 22. It is preferred that one track 52 be
provided for each of the protrusions 50, although more than one set of
the protrusions/tracks 52 may be provided. Although described as a
preferred embodiment with the protrusions 50 extending from the body 16
and tracks 52 being formed in the hub 12, it will be appreciated by those
skilled in the art that one or more of the protrusions 50 may be formed
on the hub 12 and/or that one or more of the tracks 52 may be formed on
the body 16. Reference herein shall be made to one protrusion 50 and one
track 52 with the understanding that a plurality of each may be provided.

[0036] With reference to FIG. 11, the track 52 is configured to provide at
least the first and second positions described above. With reference to
FIG. 11, the track 52 may have a first track portion 54 which extends
generally transversely to the biasing force generated by the spring 44,
represented by the arrow. A second track portion 56 communicates with,
and extends from, the first track portion 54 with the second track
portion 56 being generally aligned with the biasing force generated by
the spring 44. The second track portion 56 is formed to extend further
distally than the first track portion 54. In the first position
(represented by the numeral 1 in FIG. 11), the protrusion 50 is nested
within the first track portion 54. The cooperating interengagement of the
protrusion 50 and the first track portion 54 resists relative axial
movement between the hub 12 and the body 16 generated by the spring 44.

[0037] During use, the needle 44 is inserted into a patient to the initial
depth with the body 16 being in the first position. The body 16 acts as a
hard stop and limits the extent of insertion of the needle 14 into the
patient. Once the needle 14 is maximally inserted, and prior to actuation
of the medical injector, a predetermined extent of relative rotation
between the hub 12 and the body 16 is caused so as to urge the protrusion
50 from the first track portion 54 and into the second track portion 56.
Interengagement of the protrusion 50 and the track 52 limits the extent
of relative rotation between the hub 12 and the body 16. Once in the
second track portion 56, the spring 44 is free to urge the body 16
distally relative to the hub 12. The rotation of the protrusion 50 is a
manual trigger which allows for passive relative movement between the hub
12 and the body 16 under force of the spring 44.

[0038] With interengagement of the body 16 against a patient's skin, the
release of the spring 44 actually results in proximal movement of the hub
12 relative to the body 16. The extent of the relative proximal movement
is limited by interengagement of the protrusion 50 against the distalmost
portion of the second track portion 56. This position corresponds to the
second position of the body 16, wherein drug administration may be
achieved. As discussed above, the first and second positions may
correspond to different depths for injection, for example, with the first
position corresponding to a subcutaneous injection depth and the second
position corresponding to an intradermal injection depth.

[0039] The body 16 may be caused to be fixedly retained in the second
position. With reference to FIG. 11, the second track portion 56 may be
provided with a recess 58 into which the protrusion 50 snap engages in
the second position. The snap engagement of the protrusion 50 in the
recess 58 imparts fixed retention for the body 16 relative to the hub 12.

[0040] Although it has been disclosed to use the needle assembly 10 in
first and second positions, additional positions may be utilized. For
example, with reference to FIG. 12, the track 52 may be provided with a
third track portion 60 intermediate the first and second track portions
54, 56. The third track portion 60 may have a primary portion 62 in
communication with the first track portion 54 which extends distally
therefrom in a direction coinciding with the spring force generated by
the spring 44. The third track portion 60 further includes a secondary
portion 64 which extends transversely (transversely to the direction of
the spring force of the spring 44) between the primary portion 62 and the
second track portion 56. One or more retaining elements 66 may be
disposed along the secondary portion 64 to catch and releasably retain
the protrusion 50. Thus, during use, the protrusion 50 is initially in
the first position (represented by the numeral 1) in the first track
portion 54. The protrusion 50 is manually urged by relative rotation
between the hub 12 and the body 16 from the first track portion 54 and
into the primary portion 62 of the third track portion 60. Once in the
primary portion 62, the spring 44 causes displacement of the protrusion
50 to the second position represented by the numeral 2A. The one or more
retaining elements 66 maintain the protrusion 50 in the second position
and restrain the protrusion 50 from further distal advancement. The
restrained position may be at or in proximity to the second position and
is represented by the numeral 2B. Further relative proximal movement of
the hub 12 relative to the body 16 may be achieved by further causing
relative rotation between the hub 12 and the body 16 with the protrusion
50 being urged past the one or more retaining elements 66 and into the
second track portion 56. The spring 44 causes displacement of the
protrusion 50 along the second track portion 56. The protrusion 50 may be
urged to the third position, coinciding with the distalmost position of
the second track portion 56 (represented by the numeral 3), under force
of the spring 44 where the protrusion 50 may come into snap engagement
with the recess 58.

[0041] With reference to FIG. 12, the three positions of the track 52 may
correspond to three different use positions: a first position (position
numeral 1) corresponding to a subcutaneous depth for injection which is
achieved prior to actuation of the medical injector and drug
administration; a second position (position(s) numeral(s) 2A/2B)
corresponding to a shallower injection depth, such as an intradermal
injection depth, where drug administration is caused; and, a third
position (position numeral 3) corresponding to the distal end 28 of the
needle 14 being located proximally of the distal end 30 of the body 16,
post drug administration. In the third position, the distal end 28 is
covered by the body 16 and shielded from further contact. It is preferred
that the body 16 be fixedly retained in the shielding (third) position
after use. Any locking arrangement may be utilized to fixedly retain the
body 16 in the third position.

[0042] As will be appreciated by those skilled in the art, various
positions corresponding to various depths of injection may be provided
for the needle assembly 10. The variation of the needle assembly 10 shown
in FIGS. 1-8 may be formed with more than two positions, with additional
retention slots being provided. For example, a third retention slot may
be provided which provides for fixed retention with the distal end 28 of
the needle 14 being located proximally of the distal end 30 of the body
16 in a shielded state. Manual or passive (e.g., the layer 42) action may
be used to urge the body 16 to the third or any subsequent position.

Patent applications by Robert E. West, Basking Ridge, NJ US

Patent applications by BECTON, DICKINSON AND COMPANY

Patent applications in class Having structure for controlling depth of insertion of body piercer

Patent applications in all subclasses Having structure for controlling depth of insertion of body piercer